Astronauts spotted another shrinking lake late last month. Located in the Southern Sahara, Lake Fitri is shrinking because of a severe drought, not damming or overuse as is the case with Poyang lake in China or the Aral Sea. The lake has gone dry in the past, NASA suspects, because large dunes appear even in the deepest parts of the basin. Whether Lake Fitri is nearly empty or almost full, all water that makes it there eventually “disappears”—it’s a terminal lake with no outlet to the ocean.